Wood chipper



Dec. 19, 1967 1 FONTAINE Re. 26,323

WOOD CHIPPER Original Filed Aug. 29. 1960 2 Sheets-Sheet 6 f 4; "I; z 1Ii a IN VEN TOR.

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United States Patent 26,323 WOOD CHlPPER Paul J. Fontaine, Chicago,Ill., assignor, by mesne assignments, to Westinghouse Air Brake Company,Pittsburgh, Pa., a corporation of Pennsylvania Original No. 3,123,311,dated Mar. 3, 1964, Ser. No. 52,451, Aug. 29, 1960. Application forreissue Mar. 2, 1966, Ser. No. 535,638

14 Claims. (Cl. 241-28) Matter enclosed in heavy brackets appears in theoriginal patent but forms no part of this reissue specification; matterprinted in italics indicates the additions made by reissue.

This invention relates in general to rotary disc chippers and is acontinuation in part of an application entitled Wood Chipper, Serial No.857,838, filed December 7, 1959, now Patent No. 3,144,995. It relatesmore particularly to a new and improved chipper construction productiveof a maximum percentage of high quality wood chips.

In producing wood chips from wood stock such as slabs or the like, chipshaving certain desirable characteristics are sought. In conjunction withthis, it will be readily seen that a chipper which efiiciently produceschips at a maximum rate, a high percentage of which have these optimumCharacteristics, is not desirable.

The aforementioned characteristics are primarily desirable from a woodpulp manufacturing standpoint. The chips used for such purposes shouldhave a generally constant length parallel to the grain to insure uniformfiber length and optimum penetration during cooking. The cleanness ofcut or shear is important since in the absence thereof, squeezed chipsand poor cooking characteristics result. In conjunction with this, thechips must be cut at an angle to the grain to insure open pores for bestcooking characteristics. These and other qualities including thedesirability of insuring uniform length from chip to chip are of primeimportance.

It has been found with a conventional rotary disc chipper that avertical infeed insures the production of chips having many of thesedesirable characteristics. The vertical infeed, however, involvesfeeding slabs or logs or the like into engagement with the knifecarrying face of the rotating disc in one of the quadrants of the discat a downwardly inclined angle to the rotating face. This requiresspecially designed conveying and handling equipment for the slabs orlogs or the like since they must be initially raised and handled at alevel above the chipper itself. In addition, the chipper must be beefedup since the chipping operation is taking place substantially on a levelwith the horizontal axis of the chipper disc and, consequently, a highrange of forces are thrown upon the chipper mountings during thechipping operation. It will be readily seen that the use of the verticalinfeed construction injects construction and operational problems whichrequire expensive and, consequently, undesirable solution.

The horizontal infeed construction has been used for some time becauseof simplicity of construction and ease of operation. Horizontal infeedrotary disc chippers, however, have heretofore been incapable ofproducing wood chips, for example, in quantities having a maximumpercentage of superior quality chips. The ordinary horizontal infeedchipper sacrifices optimum performance for the ease and low expense ofoperation inherent in this construction.

Accordingly, it is a primary object of this invention to provide arotary disc chipper which produces a maximum percentage of high qualitywood chips.

Another object is to provide a rotary disc chipper having a horizontallydisposed infeed which produces chips having the aforedescribedcharacteristics.

Re. 26,323 Reissued Dec. 19, 1967 Another object is to provide a chipperhaving an infeed chute extending horizontally from the face of thechipper disc in one of the lower quadrants of the disc.

Yet another object is to provide a rotary disc chipper having avertically disposed anvil aligned generally with the vertical [axis]radius of the knife carrying disc face so as to provide optimum knifeedge utilization.

Still another object is to provide a rotary disc chipper having ahorizontal infeed which assures slab feed such that the width of a slabis always against the fixed anvil.

Another object is to provide a chipper having a knife orientation suchthat a downward force component is imparted to material fed to thechipper to prevent vibration and chattering of the material during thechipping operation.

Yet another object of this invention is to provide a chipper having aninfeed chute extending horizontally from the knife carrying face of thechipper disc at an optimum angle to the face.

Still another object is to provide a chipper which produces high qualitychips yet is relatively inexpensive and requires no special slabhandling equipment.

Yet another object is to provide a horizontal infeed chute for a chipperof the aforedescribed character wherein slabs having enlarged butt endsare easily accommo dated.

These and other objects of this invention will be found in the followingspecification and claims wherein like reference numerals identify likeparts throughout.

The invention is illustrated more or less diagrammatically in thedrawings wherein:

FIGURE 1 is a front elevation with parts broken away of a wood chipperembodying this invention.

FIGURE 2 is a view taken along line 2-2 of FIG- URE l, and

FIGURE 3 is a view taken along line 33 of FIG- URE 2.

Referring to FIGURE 1, the wood chipper includes an upright housingindicated generally at 2, adapted for mounting on a horizontal surface.Pillow blocks 3 formed integrally with opposite sides of the housingform bearing means for shaft 4 which is adapted to rotate about ahorizontal axis transverse to the housing. One end of the shaft 4extends beyond a corresponding bearing and has mounted adjacent itsouter end a series of pulleys 5. Pulleys 5 are driven through a seriesof conventional V-belts 6 from a source not shown. A generally circularchipping rotor indicated at 9 is mounted on shaft 4 within the housing 2for rotation with the shaft in a plane perpendicular to the axis of theshaft. Adjacent the lower quadrant of the rotor 9 and extending throughthe housing 2 is a wood stock feed chute or feed spout indicatedgenerally at 10.

The chipping rotor 9 comprises a disc 13 fashioned of heavy steel stockhaving a knife carrying face 14 and a rear face 15. Chip remover fans 16are secured to the rear face at generally regularly spaced intervalsaround its periphery in a conventional fashion.

Chipper knives 17, which might be of the construction shown in theaforementioned co-pending application, extend generally radially of theface 14 but are offset 3 to 7 degrees from a radius of the face. To bemore explicit, the outer end of the chipper knife is in trailingrelation of a radius of the face to which the inner end of the chipperknife is in leading relation. This is shown graphically at 18 in FIGURE1, for example. The reason for this offset mounting will be more fullyexplained in the description of the use and operation of this invention.

The relationship of the wood stock feed chute 10 to the housing 2 andthe chipping rotor 9 is best seen in FIGURES 1 and 2. The feed chute 10pierces the housing 2 in a lower quadrant of the chipper rotor. A plate21 having a vertically extending flange 22 forms one side of the feedchute 10. A thin fillet plate 23 connects the inner end of plate 21 withthe housing 2. The fillet plate might be removable, for example, toprovide an inspection plate. Pour horizontally extending slots 24 extendthrough the plate 21. A pair of internally threaded holes 25 arevertically spaced in the flange 22.

An anvil or bed knife carrying slide 28 is secured to the inner wall ofthe plate 21 by bolts 29 which extend through the slots 24 and arethreaded into internally threaded holes, not shown in the slide. Washers30 prevent the heads of the bolts 29 from passing through the slots 24.

Vertically spaced on the outer end of the slide 28 are internallythreaded collars 31. Adjusting bolts 32 extend through the collars 31into threaded engagement with the internally threaded holes 25 in theflanges 22. Lock nuts 33 on the bolts 32 lock the bolt in apredetermined position relative to the collars 31. Consequently, theslide 28 may be locked in a predetermined position relative to the plate21.

At the inner end of the plate 28, vertically extending notch 35 isformed. An anvil or bed knife 36, which might be comprised of Stelliteor any other hard metal is snugly seated in the notch and held thereinby bolts 37 extending through the slide 28 adjacent the notch 35. Theplate 21 is positioned so that slide 28 will carry anvil 36 into properrelationship with the cutting surface of the chipper knife at a point onor slightly behind the vertical radius of the chipper disc 13 as viewedtoward the face of the disc. Anvil 36 extends vertically and is parallelto the aforementioned radius.

Shown in dotted lines in FIGURES 2 and 3 is the base plate 40 of thefeed chute. A base slide 41 having a downwardly extending flange 42 atits outer end overlies plate 40. The base slide 41 has threaded into itsbottom face a set of bolts 43 which extend through longitudinallydisposed slots 44 in the plate 40 and secure the slide 41 to the plate40 for sliding movement relative thereto in a direction parallel to theslide 28. The flange 42 has an adjusting bolt 45 extending through aslot 46 therein into threaded engagement with base plate 40. Bolt 45carries lock nuts 47 on its outer extremity. Limit stop bolts 48 extendthrough the flange on either side of the bolt 45 and engage the outerend of the base plate 40 to limit movement of the base slide 41 as it isadjusted by bolt 45 relative to the chipper knives.

A curvilinear plate 50 forms the other wall of the feed chute 10 andextends through and into the housing 2, as is seen in FIGURE 2. It joinsrelatively narrow base slide 41 at the bottom and irregularly shapedcover plate 51 at the top.

Cover plate 51 overlies the chute 10 and connects plate side walls 21and 50. The cover is irregularly shaped in such a manner as to leave anenlarged path 52 adjacent the upper corner of the chute 10 opposite theanvil.

The chute 10 is constructed and arranged such that slide 28 extends atangle of approximately 38 degrees to the knife carrying face 14 of thechipper disc 13.

The use and operation of this invention are as follows:

In the production of wood ships for ordinary use in the manufacture ofwood pulp, the rough wood stock employed is commonly in slab form. Thisinvention is consequently primarily concerned with the handling of woodslabs but it will be understood that many advantages are also inherentwhich apply equally as well as to other forms of wood stock, such aslogs, or other materials entirely, for example.

The feed chute 10 is constructted and arranged such that it extends atan angle of approximately 38 degrees to the face 14 of the chipper disc13. Consequently, wood stock passing through the chute into engagementwith the chipper knives 17 will engage the face at this angle. An angleof 38 degrees has been found to best insure the resulting chips havinguncrushed, open, and consequently desirable pore structure.

The wall 21 of chute 10 is positioned such that it supports the verticalslide 28 in a manner which insures the anvil 36 being in proper relationto the chipper knives. That is, at a point on or slightly behind orahead of the vertical radius of the chipper disc 13 as viewed toward theworking face of the disc. This relationship is best seen in FIGURE 2 andhas been found most desirable in practice. The anvil lies, however, forall practical purposes, substantially along the vertical radius of thechipper disc such that maximum knife edge exposure is obtained when theknives pass the anvil 36. Slide 28 is horizontally adjustable on plate21 to provide proper adjustment of the anvil 36 relative to the chipperknives 17. This adjustment feature is also found in base slide 41.

Chipper knives 17 are mounted on the knife carrying face 14 of thechipper disc 13 at an angle of approximately 3 to 7 degrees from aradius of the disc. This insures as will be seen in FIGURE 1, that theinner end of the chipper knife will lead the outer end through achipping pass by a slight amount. It will consequently pass the anvilslightly in advance of the outer end. This produces somewhat of ascissors effect, as might be easily seen in FIGURE 1. and insures that aslab of wood fed through the chute 10 into engagement with the chipperknife carrying face 14 is continually urged into the lower corner of.the chute 10 adjacent the anvil. The result is an elimination ofvibration or chattering normally found in chippers of this type whichoccurs when the wood stock has an opportunity to move up and down on theanvil face as successive chipping blades engage it.

As will be seen in FIGURE 3, the cross section of the wood stock feedchute 10 is irregular along its outer wall 50 and cover plate 51. Byvirtue of the curvilinear shape of the outer wall 50, a mostadvantageous feed attitute of the slab is insured. As the slabs enterthe feed chute 10, they are forced up on edge by the curvilinear walland consequently come into engagement with the rotating chipper kniveswhen their widths are aligned with and in general, in engagement with,the anvil 36. Consequently, the best chipping relationship is attainedat the outset since the slabs will be held along their width tightlyagainst the anvil by the rotating knives and no rolling or turning ofthe wood stock will be effected. Such an initial turning of a slabresults in the production of a relatively high percentage of poor woodchips. Such poor chips were commonly produced in abundance when slabswere fed in such a manner that their width lay along the base plate of afeed chute. In this attitude, the chipper knives would successivelyengage a slag and tend to turn it slowly up into on-edge relationship.During this transition period, chips of very poor quality havingsqueezed pores, inconsistent lengths and uncleanly sheared faces arenormally produced.

The cover plate 51 is constructed such that the chute will readilyaccommodate slabs having large butt ends, a common occurrence in woodstock of this type. As again will be seen in FIGURE 3, a considerablyenlarged area 52 is formed in the upper and outer corner of the chute10. Thus, when slabs having large butt ends are fed into the chipperchute, butt ends first, the slab will be able to pass through the chutewith case. It will be understood, of course, that the chips cut from theenlarged butt end will be of lesser quality since they will be cut fromthe slab while it is constantly turning inwardly in a tendency to placeits width against the anvil 36, but after the butt end has been strippedoff the slab,

a high quality chip will again be produced throughout the length of theslab.

What has been shown then is a wood chipper of the rotary disc typehaving a horizontal infeed which, nevertheless, produces a maximumpercentage of chips of opti mum quality. This horizontal infeed permitsinexpensive construction of the chipper itself and lower horsepowerdemands on the driving motors. These advantages are provided by theparticular construction of the infeed chute and its relation to therotating chipper knives.

It will be seen that slabs will be delivered into engagement with therotating chipper knives at attitudes productive of this maximumpercentage of high quality chips and the maximum knife edge area will beutilized in each chipping pass since the anvil is generally along thevertical [axis] radius of the chipper disc 13.

Vibration and chattering is prevented, due to the slightly offsetchipper knives 17 engaging the wood stock such that the outer end of theknife trails the inner end with regard to a radius of the chipper disc.The wood stock is firmly held in one attitude by virtue of thisconstruction.

What has been shown and described is a new and improved rotary discchipper which is relatively inexpensive to construct and operate andwhich is productive of a maximum percentage of high quality wood chips.It is intended that the foregoing description be illustrative only,however, and not definitive and the scope of the invention should belimited only by the appended claims.

I claim:

1. A method of reducing an elongated slab of wood into wood chips in awood chipper having a chipper disc rotating about a horizontal axis witha plurality of chipper knives on one face moving past a fixed verticalanvil positioned generally parallel to the vertical radius of the disc,including the steps of positioning a slab below the axis of rotation ofthe disc, feeding the slab horizontally at an acute angle to the face ofthe disc, contacting the slab in an on-edge relationship with thechipper knives, keeping the width of the slab against the anvil, andmaintaining the slab in on-edge relationship With the disc so that theknives cut across the slab.

2. A wood chipper for processing slabs of wood or the like comprising ahousing, a disc mounted within said housing and adapted for rotation inone direction in a substantially vertical plane, a substantiallyradially extending chipping knife seated in one face of said disc, asubstantially vertical anvil fixedly secured within said housing andextending substantially parallel to the vertical radius of said disc ina lower quadrant of said disc, a horizontally disposed feed chuteextending laterally of said disc and adapted to deliver a slab of woodinto engagement with said face in front of said anvil, said feed chutecomprising a vertically extending inner Wall in alignment with ansupporting said anvil, a relatively narrow base plate joining said innerwall at its base and forming the bottom of said chute, an outer guidewall diverging upwardly from said inner wall and joining said base, saidguide wall extending substantially above the level of said inner wall,said guide wall having a lower portion extending inwardly and an upperportion extending outwardly, and an irregularly shaped cover plateoverlying said walls so as to present an enlarged area extending thelength of said chute adjacent the junction of said guide wall and saidcover plate and thus permit passage of wood slabs having abnormallylarge butt ends.

3. A wood chipper for processing slabs of wood or the like comprising ahousing, a disc mounted within said housing and adapted for rotation inone direction in a substantially vertical plane, a substantiallyradially extending chipping knife seated in one face of said disc, asubstantially vertical anvil fixedly secured within said housing andextending substantially parallel to the vertical radius of said disc, ahorizontally disposed feed chute forming an angle with the face of saiddisc, said feed chute extending transversely of a lower quadrant of saiddisc and including a first side Wall extending in substantially verticalalignment with said anvil, a relatively narrow base, and a guide wallconnected to said base and forming the opposite side of said chute, saidguide wall diverging upwardly from said first wall, said guide wallhaving a lower portion extending inwardly and an upper portion extendingoutwardly so as to tend to maintain said slab in one-edge relationshipthroughout the passage of said slab through the feed chute.

4. In a chipper having a rotary disc fitted with knives, said discknives having cutting edges uniformly spaced away from the plane of thedisc and a coacting bed knife having a straight cutting edge, a feedspout comprising a tubular member extending into the chipper adjacent tothe bed knife, said member having an inner end and an outer end, saidinner end being disposed in a plane substatially parallel to the planeof the disc and to the cutting edge of the bed knife, said member havinga flat side wall disposed parallel to the straight cutting edge of thebed knife, a top wall disposed substantially at right angles to the sidewall and a curved wall connecting the side and top walls.

5. The structure as claimed in claim 4 wherein the side wall is disposedat an acute angle to the axis of rotation of the disc.

6. A wood chipper for processing slabs of wood or the like comprising ahousing, a disc mounted within said housing and adapted for rotation ina substantially vertical plane, a substantially radially extending knifeon one face of said disc, a vertical anvil fixedly secured within saidhousing and extending substantially parallel to a vertical radius ofsaid disc, a horizontally disposed feed chute extending laterally ofsaid disc, said feed chute forming an angle with the face of the disc,said chute having a side wall extending in substantially verticalalignment with said anvil, and an opposed guide wall, said guide wallhaving a lower portion extending inwardly and an upper portion extendingoutwardly to maintain said slab in on-edge relationship with said discand insuring engagement of the width of said slab with said anvilthroughout the length of the slab.

7. In a wood chipper, the combination of a chipper disc mounted forrotation in a generally vertical plane, said chipper disc being adaptedto receive knife means mounted on the working face thereof;

a housing enclosing the chipper disc, said housing having a chip outlet,

a generally horizontally disposed fccd chute which terminates at a feedchute inlet at the housing, and

a chipping anvil associated with the housing and feed chute at the feedchute inlet,

said anvil lying substantially along the vertical radius of the chipperdisc as viewed toward the working face thereof.

8. The wood chipper of claim 7 further characterized in that the anvillies slightly behind the vertical radius of the chipper disc as viewedtoward the working face thereof.

9. The wood chipper of claim 7 further characterized in that the anvilis coextensive with the vertical radius of the chipper disc as viewedtoward the working face thereof.

10. The wood chipper of claim 7 further characterized in that the anvillies slightly ahead of the vcrlical radius of the chipper disc as viewedtoward the working face thereof.

11. The wood chipper of claim 7 further characterized in that the feedchute narrows toward the chipper disc to facilitate the placement of thewidth of the wood stock flat against the anvil.

12. In a wood chipper, the combination of a chipper disc mounted forrotation in a generally vertical plane, said chipper disc being adaptedto receive knife means mounted on the working face thereof;

a housing enclosing the chipper disc, said housing having a chip outlet,

a generally horizontally disposed feed chute which terminates at a feedchute inlet at the housing, and

a chipping anvil associated with the housing and feed chute at the feedchute inlet,

said anvil being aligned generally with the vertical radius of thechipper disc as viewed toward the working face thereof, at least onepoint of the anvil coinciding with the vertical radius of the anvil asviewed toward the working face thereof.

13. In a wood chipper, the combination of chipper disc means havingknife means associated therewith,

housing structure associated with the chipper disc means,

a generally horizontally disposed feed chute having a feed chute inletat the housing structure, and

a chipping anvil associated with the housing structure and feed chute atthe feed chute inlet,

said generally horizontally disposed feed chute having means, at thefeed chute inlet end, which turns wood stock into an oil-edge positionin which the wood stock is urged into firm, non-turning contact with theanvil from the commencement of the chipping action,

said means including oppositely located side walls which are spacedapart from one another a distance less than the maximum width of thewood stock at their exit adjacent the chipper disc.

14. The wood chipper of claim 13 further characterized in that the feedchute narrows in a direction looking toward the chipper disc wherebywood stock having a flat side will be turned into an on-edge positionprior to commencement of the chipping action.

References Cited The following references, cited by the Examiner, are ofrecord in the patented file of this patent or the original patent.

OTHER REFERENCES Brown: Pulp and Paper Magazine of Canada, v01. 49,number 11, pages -97. (Copy in Scientific Library.)

Daspapier (German), vol. 14, pp. 56-58 (Jam-June 1960). (Copy inScientific Library.)

The Wood Chipper, Paper Industry and Paper World for September 1948.(Copy in Div. 30.) Pages 883-888.

WILLIAM W. DYER, JR., Primary Examiner.

W. D. BRAY, Assistant Examiner.

